unsolvable engine problem

[GlynRS2]

Timucin,
It sounds like you have tried about everything you can, and I am sure it is costing you quite a bit aswell as a lot of time. The only thing I would suggest is getting the car on a rolling road and having the thing tested dynamically. Obviously that may not be that easy in Turkey. In the UK it sounds like a job for Geoff at AmD - they have a 4WD and all the Bosch diagnostic kit etc. In the end it may be a relatively simple fault - but it is just finding out what exactly it is.
Just a thought, did it not start almost straight after changing your exhaust system? I know sometimes lack of back pressure can cause problems & make the ECU back off into safety mode. This can also happen if the ECU thinks the turbo is getting too hot - have you checked the turbo coolant pump as per S2 Central Technical advice section. LINK If you still have the original exhaust it might be worth just refitting that & seeing if it still happens. [img]images/graemlins/confused.gif[/img]
Hope you get it sorted - good luck.

[timucin]

turbo heat: possible but
exhaust back pressure:possible but
fuel octane low:possible but
the car was running ok ,it suddenly happened

np i can wrapthe turbo,fabricate some heat walls but i dont believe this is the fault.
back pressure:its not important as it is on a atmospheric car on turbo cars,bigger better for sure

confused........

[timucin]

today:
i have checked :
exhaust manifold for crack
intake manifold for crack
gaskets
wastegate diaphragm

nothing wrong

[timucin]

[img]images/graemlins/24430-audibash.gif[/img]

[smurfbus]

you seem to go into somekind of semilimpmode for a while.

I think ecu gets a trigger from one of the sensors going over its limit at 5000rpm (maybe a boost spike). try pressure relief valve paraller with n75 to limit boost. first try 15psi then go higher. can you log your maf, boost and timing?

[timucin]

can you log your maf, boost and timing?
-no
will translate your post to my mechanic,i dont know anything about these stuff
thnx for help

[smurfbus]

can you unplug the maf-wire and test without it?

cold weather means more g/s so your maf could also go over its limits?

[timucin]

ok i can do that.will post the result.i ddnt know car would start without that maf cable plugged.gimme 10 minutes will do that and reply

[timucin]

i unplugged and worked the car,also dd small test run.

[timucin]

weather is :2 degrees
there was no light inside the car showing unplugged something,i was expecting a red or yellow light
w/o : maf car runs but sometimes makes pa-pa-pa-pa but it runs. turbo came up to 20 psi
i dont know what sholud i understand from this?

[smurfbus]

did it go past 5000 rpms and still have good boost? if not(still boost cut to 6psi) then your maf should be fine. If there was no problems at 5000rpm then your maf is to blame!

your car should now run based on rpms so boost at low rpms is lower and usually the engine runs richer(hence the papapapa).

I'm not familiar with your engine so I'm just speculating as I have S4 2.7t

[timucin]

LOL!
dont remember 5000rpms will try again

[timucin]

my last desicion: will leave the car to a audi service tomorow morning, if they fix ,its fixed if they cant i am not gonna touch it untill i go to belgium with it.
no more try or questions about this failure...

[img]images/graemlins/3flypigs.gif[/img]

[PP]

sensible decision - well done. [img]images/graemlins/clap.gif[/img]

[timucin]

[img]images/graemlins/wink.gif[/img]